Automatic thermo mechanical kick-off or disconnecter



Nov. 5, 1935- s. A. DUVALL 2,020,110

AUTOMATIC THERMO MECHANICAL KICK-OFF OR DISCONNECTER Filed March 1. 19-53 5 Sheets-Sheet 1 FIG,.1..

'I g I i 14 Stanley A .DuvaLL,

S. A. DUVALL Nov. 5, 1935.

AUTOMATIC THERMO MECHANICAL KICK-OFF OR DISCONNECTER 3 Sheets-Sheet 2 Filed March 1, 19:53

Fee

FIG. 4

Gum

Nov. 5, 1935. s. A. DUVALL, 2,020,110

.- AUTOMATIC THERMO MECHANICAL KICKOFF OR DISCONNECTER Filed March 1, 1933 3 Sheets-Sheet 3 Qwucmlm Stanley A. Duvau Patented Nov 1935 UNITED. STATES PATENT- OFFICE I tmJ-l.

su'rous'no CAL 111mm non-or!- oa DIBCONNEO'I'EB Stanley Alexander Duvall, Louisville. mum um-nsuuuusmaesmummxy. Applicaflon March '1, 193:, Serial No. mass 11 can. (61. 219-25) nectedtosaidplugsandinordertoheattheironitwas slidup the runway until its plugs enlo gagedinthecooperatingjacks. Inordertoprevent overheating of the iron I provided a thermostat inside the housing, in position to be heated from-theheeloftheiron Whenthe ironreached the desired temperature this thermostat would 20 break the heating circuit.

I have found that in practice a thermostat such as I have described is liable to get out of order fromtherepeated clashingoftheironagainst the housing and the repeated and many'times B multiplied beatings and cooiings to-which it is subjected. I have therefore designed the improved device de'scribed herein for controlling the heat. which consists essentially of what I I shall call a kick-oif device and a thermostatic to latch controlling the same. This kick-oil! device includes one or more mechanical plungers or the equivalent thereof which when the iron is in position on the rlmway with its plugs in the jack for heating are pressed back and latched. Con- 36 trolling the latch is a thermostatwhich normally holds the latch in enga ed position and which is in immediate conductive contact or equivalent heating relation with the heel of the iron. when the'latter reaches the desired temperature the i0 thermostat is operated to trip the latch and the kick-oiithenacts'topusttheiron downtherlmway a suflcient distance so that its plugs are clear of the jacks and the heating current in the main circuit is thereby cut off. The thermosat is, thus employed is made rugged and needsnoflne adjustment. It is therefore free from the objections heretofore mentioned against the electrical thermostat referred to.

I intend to include in the foregoing description so all forms of a trip and kick-oil, which do not require such sensitive adjustment as the ordinary electrical thermostat. I shall describe hereinafter two forms of kick-oil, one having two -plungers withthe thermostat and latch inside 5 the housing and another form having a single plunger and a thermostat constituting in itself thelatchandlyingbeneaththeheeloftheiron outsidethehousing. Ishallalsodescribeamodiflcation in which the thermostat trips a mechanical snap switch located inside the housing B and acting when tripped to break the main circuit. Thisisfreefromtheobjectionstoasensitive thermostatbe'cause the switch can be made rugged and substantial. Other possible changes and modifications will sufllciently appear to those skilled in the art from the detailed description hereinafter, and it is to be understoodthat I am not limited to any one form but contemplate all such changes and modifications as fall fairly within the scopeand purview of the appended claims.

-My invention is illustrated in the ing drawlngslinwhich Fig-1 is a side view,of the complete device and parts of the housing broken away. showing the iron in position to be'heated and the kickofllatched...

Fig.2isaviewsimilartoFigJbutshowing thelatchtrippedandtheironkickedotl'todisconnect its heating plugs from the jacks in the housing.

Fig. 3 is a horizontal section on the line 3-3 ofIigJlookinginthedirectionofthearrow.

Fig. 4' is a section on'the line 4-4,of Fig. 1 looking in the direction of the arrow. Fig.5isa :1 ticsideviewofthemodiil-y oation having a single plunger and a combined thermostat and latch outside the housing.

Fig.6isa'diticendviewofthesame parts with theironcold.

Fig.7isasimila'rdiac 'endviewwith theironassumedtobehotandthethermostat thereby-straightened out, the kick-on being shown in dotted lines.

Fig.8isatic viewshowingas'nap switchinthemaincircuitcontrolledbyathermostat and plunger similar to those in Figs. 5,6,

'and 7.

Referring to the drawings and particularly to Figs. 1, 2, 3 and 4, I is an elect'ricflatironand 45.

.2 is a stand therefor both of the same general type of construction as those shown in my prior application hereinbefore referred to. The stand 2 is essentiallyametal strip having afacing or cover-30f orsimilarheatresistingma- .terial. 'I'hestand2issecuredatoneendtothe ironing table it by means of a stud It on the clamp ll. Mounted on this stand is a housing, shownin enlargedvlewsinl lgs3and4and having end pieces II and iloi'insulatingmaterial with a metal cover 5. Heating current is brought head 20 and normally impelled forward in their respective bearing tubes I1 'by compression springs l2. When the plungers H v are forced back the cross-head is engaged by the latchil connected by a chain 22 to the thermostat 23 which is secured to the and piece. it in such a manner as to have metal parts such as rivets or screws directly in contact with the heel of. the iron when in heating position, as in Fig. '1.

The operation of the device thus described is as follows: To be heated the iron is slid up on the asbestos cover a betw'eenthe guides 41 until its plugs ii engage in the jacks l0, when the heel of the iron will be in contact with the metal parts connected to' the [thermostat and the plungers' II will be forced back and latched. When the iron however gets too hot vor about 400 F. the thermostat 23 "straightens up and lifts the latch 2| which trips the cross-head 20 and allows the springs I! to force the plungers' ii forward 'againstthe iron so as to kick the iron away from the housing with its plugs 0 disconnected as shown in Fig. 2. I

The foregoing is the form of my device in which all the operative parts are included within the housing, but in Figs. 5, 6 and 'l I have shown a simpler construction which has a single plunger and combined thermostat'and latch lying outside of the housing. -In, these figures the iron rests as before on the slide. or stand 2 and its plugs 8 engage the jacks III as before. When in this position, the heel of the iron'rests upon a strip of thermostat metal 30 which extends across the stand or slide just outside of thehousing and is normally slightly bowed as shown in Fig.6. A single plunger 3! with a compression spring 32 is journalled so asto slide in suitable hearings in the end pieces l0 and i9. when the iron is cold and the thermostat metal 30 is therefore bowed said metal strip lies in the path of the plunger 3| as shown in Figs. 5 and 6, the plunger 3| being shown in dotted lines in Figs. 6 and '7. When the iron gets too hot however or about 400 F. the

thermostat metal strip 30 straightens out as shown in Fig.7 and releases the plunger 3|, which thereupon kicks the ironforward so as to dis connect its plugs and leave it in the same position as shown in Figfz.

Referring now to Fig. 8, I have shown therein a snap switch 40 actuated by a plunger similar to'that shown in Fig. 5. The contacts of this switch are of the familiar knife blade type connected as shown in the main circuit so that when the thermostat 4i acts'to raise the latch 42 the knife blade 43 will snap away from the fixed contact 44. The heating circuit being thus opened it is unnecessary to kick the iron away and the spring 45 on the plunger may be made too weak to kick the iron away or if preferred it may be made to act as a kick-off in addition to opening the circuit.

What I claim is:

1. An electric flatiron containing a heating element and terminal contacts therefor in combination with a stand comprising a runway for the iron, terminal contacts adapted to receive the contacts on the iron when the latter is on the runway, a mechanical kick-off normally latched when the iron is in position to be heated, a latch controlling the same and a thermostat directly exposed to the heat of the iron and controlling said latch, said kick-,ofl when released acting di- 1 rectly upon the iron to push it down the runway and disconnect the heating contacts. 2. The combination described in claim 1, in

which the kick-off consists of a plunger element,

a helical spring normally pressing the same for- 11 ward, a latch engaging the plunger and a therto an ironing surface, insulating end pieces for said housing, a power jack connection in one of said end pieces, a pair cfjacks connected thereto 2 and extending through the other end piece to receive the terminal contacts 'of the'iron when the latter is in heating position on the runway, plunger means carried by' the housing and adapted to slide in bearings below said jacks, 2 spring actuating means for moving said plunger means against the iron, a latch for said plunger means, a thermostat connected so that when heated it will retract said latch, and means for conveying heat from the heelof the iron when 3 in heating position to said thermostat.

4. An electric flatiron containing a heating element and terminal contacts therefor in combination with a stand comprising a runway for the iron, fixed terminal contacts adapted to receive 3 the contacts on the iron when the latter is on the runway and in heating position, a strip or bar of thermostatic metal extending across the runway in contact with the iron when the latter is in heating position, a mechanical kick-off adapted when 4 actuated to push the iron a limited distance down the rlmway and thereby disconnect its-terminals from the fixed power terminalsor Jacks, said thermostatic bar when cold shaping itself so as to lie in the path of and to constitute a latch for said 4 kick-off device but also adapted when heated to a predetermined limit as for example 400 F. to alter its shape so as to release said kick-off and push the iron away so as to disconnect its heating element from the power supply. l

5. An electric flatiron containing a heating element and terminal contacts therefor in combination with a stand comprising a runway for the iron, terminal contacts adapted to receive the contacts on the iron when the latter is on the i runway, a mechanical kick-off for separating the contacts, a thermostat adapted to receive heat from the iron and constitute'a latch for said kick-off and means for storing kick-off operating energy in the kick-off by movement of the iron 1 against an element of the kick-off.

6. The combination of fixed power contacts, an electric flatiron with cooperating contacts, kickoff mechanism adapted to disconnect said contacts, a thermostat bar adapted to receive heat from the iron and constitute a latch for the kick-off device, and means for storing kick-off operating energy in said mechanism by movement of a portion of the iron against an element of said mechanism.

'7. The combination of fixed power contacts, an electric flatiron with cooperating contacts, kickof! mechanism adapted to disconnect said contacts, a latch for the kick-01f mechanism, thermostatic means for controlling said latch adapted to receive heat from the iron, and means for storing kick-off operating energy in said mechanism by movement of a portion of the iron against an element of said mechanism.

8. An electric flatiron containing a heating element and terminal contacts therefor in combination with a stand comprising a runway for the iron, terminal contacts adapted to receive the contacts on the iron when the latter is at one end of the runway, a mechanical kick-off carried by the stand and adapted to move the iron from said end of the runway, a latch normally restrain ing the kick-oil, and thermostatic means adapted to receive heat from the iron to release the latch.

9. The combination of an electrically heated flatiron having electric contacts, a support having fixed contacts, a mechanical kick-ofi adapted to disconnect said contacts, a latch for normally restraining the kick-off, and thermostatic means adapted to receive heat from the flatiron' for releasing the latch.

10. The combination of an electric flatiron containing a heating element and plug contacts therefor, a stand comprising an insulated housing at one end containing a supply jack, and

other jacks extending across the housing for engagement with the plug and the plug contacts of an electric flatiron, a pair, of parallel plungers mounted below the jacks within the housing, a crosshead to connect the plungers together compression springs adapted to normally impel the parallel plungers forward, a latch to hold the parallel plungers within the'housing, and means to release the latch from holding the plungers within the housing, when an iron resting on the stand reaches a predetermined temperature.

11;- The combination of an electric iron having plug contacts therefor, a stand having contacts cooperating with plug contacts when an iron is in operative position on the stand. plunger -in non-iron moving position and thermostatic means in the stand responsive to temperature of 20 the iron to operate the latch whereby the plunger will cause the iron to move to inoperative position when the iron reaches a certain temperature.

STANLEY ALEXANDER DUVAI/L. 2s 

